1. Field of the Invention
The present invention relates to a fuel oil amount indicator of a measuring apparatus for displaying an amount of a fuel oil fed to a vehicle or the like at an oil station.
2. Description of the Related Art
Usually, a measuring apparatus for feeding a fuel oil which is installed at an oil station to feed the fuel oil is provided with a fuel oil amount indicator for displaying the amount of the fed fuel oil. For example, in a ground installation type of measuring apparatuses, a main body case is disposed on an island provided in a site of the oil station, and the fuel oil amount indicator is attached to a display unit case on an upper side of the main body case. As the fuel oil amount indicators, various types have been used, but in recent years, liquid crystal displays have been used. The present applicant has disclosed a technique regarding a display device of a measuring apparatus in which a diffusion plate for diffusing light and a coloring plate for transmitting light are disposed on a back face side of a transmission type liquid crystal display panel, and a back light illumination is disposed on a back face side of the coloring plate (e.g., refer to Japanese Patent Application Laid-Open No. 2001-242798 (pages 2 to 3, FIGS. 1 to 4)).
In a conventional liquid crystal display, display elements of liquid crystals used do not emit light by themselves, and therefore, an illumination such as a back light is provided so that the liquid crystal display can be used at night. However, a lifetime of the back light is short, and for the exchange of the light, maintenance work which is troublesome and needs expert knowledge might be required. Moreover, the conventional liquid crystal display tends to be hard to see an image thereon, when it is exposed to the sunlight in the outdoors.
The present invention has been developed in view of the foregoing situation, and it is an object of the present invention to provide a fuel oil amount indicator of a measuring apparatus which makes it possible to prolong a lifetime of the indicator and to omit maintenance work and which is easily viewable at any time of the day or night.